Why does Australia Post have a tracking system?

Why does Australia Post have a tracking system when it does not actually do any tracking?  In the last couple of months we have purchased two fairly expensive items online, and both were sent with a tracking number.  After the first item had not arrived within a reasonable time, we went on Aust. Post site to track it.  They acknowledged it has been received and given a tracking number, but for five days - nothing!  Now this item was posted from Sydney, we live in country SA, more than 600kms from Adelaide and 38kms from our nearest regional city and PO.  Surely our parcel would have passed through some sort of "tracking system" in those five days.  It eventually did arrive and the following day the Aust Post tracking site stated that it had been received at our nearest PO.  Yeah we know!!!  We are now waiting on another parcel.  All the tracking site tells us that it was posted 5 days ago.  I guess it's no surprise that postage in Australia is so expensive - we have to pay for high tech tools that don't actually do anything.